These are 5 pages which go over how to use a comma between a city and state in a sentence. It also goes over what to do if you continue a sentence after you list the state. There is a practice quiz and a quiz. These pages are by Lowell Reiff.
Look for my Common Core Daily English Language Arts Practice Pages/Morning Work also. I also offer units for every CCSS in Language for 3rd grade. It is also bundled and available.